Surface Go 3 USB-C Charging Puzzle

[Lobalobo]

The USB-C port of my Surface Go 3 will charge the device when plugged into a wall outlet through a 100W, "15V=3A" wall charger.

Using the same cable, the device will not charge (though it did once) when attached to a 63W Eggtronic battery with the following Voltage specifications:

As I mentioned, this battery worked once to charge the Go 3, but now will not even though it seems (at least to me) to meet these minimum specifications:

• Surface Go models: Require 30 W PD (15 V / 2 A) or 45 W PD (15 V / 3 A)

What am I missing? Thanks in advance.

 

[GoMan]

The minimum specifications you provided are from a data sheet by a company that sells a Surface Connect to USB-C charging cable.

Fast charging via the USB-C port has a different requirement, as the Surface Go 3 (and other Surface devices) will request 20V from a PD power source. As a result, Microsoft recommends a USB Type-C PD charger rated at 60W or higher. While your Eggtronic Laptop Power Bank will furnish 20V, the 45W rating for the USB-C port may be a little too low for comfort and may provide inconsistent results depending on the state of charge of both devices.

Although you don't mention the brand and model of the 100W charger at the beginning of your thread, given its 100W maximum rating, I would think it should have the capability to provide 20V / 5A.

 

[Lobalobo]

Fast charging via the USB-C port has a different requirement, as the Surface Go 3 (and other Surface devices) will request 20V from a PD power source. As a result, Microsoft recommends a USB Type-C PD charger rated at 60W or higher. While your Eggtronic Laptop Power Bank will furnish 20V, the 45W rating for the USB-C port may be a little too low for comfort and may provide inconsistent results depending on the state of charge of both devices.

Thanks so much for such an informative and quick response. Hope you don't mind a couple of quick follow-up questions: First, the Eggtronic Power Bank is rated at 63W, so I'm not sure I quite understand how the "45W rating for the USB-C port may be a little too low for comfort." Is it that 63W , 20V of the Eggtronic is Power Bank is too close to the minimum on both measures, leading to inconsistent results? In any case, do you know of a small Power Bank that has high enough specs to work reliably? The issue matters to me because when I travel with just the Surface Go 3 it would be a help if I didn't need to also carry a devoted charger, using the Power Bank for both phone and tablet. Thanks.

 

[GoMan]

The Eggtronic Laptop Power Bank provides multiport charging capabilities. One USB-C PD and two USB-A ports permit the charging of multiple devices simultaneously. The 63W total figure combines the power output of the USB-C PD port at 45W and the USB-A Output 1 port at 18W, which may be confusing because a single device will never be able to take advantage of the total 63W output.

Output:
USB-C: 5V⎓3A / 9V⎓3A / 12V⎓3A / 15V⎓3A / 20V⎓2.25A

Power = Current × Voltage:
2.25A x 20V = 45W

Based on the above calculation, 45W is the maximum power the USB-C port on the power bank can supply, which is quite a bit shy of Microsoft's minimum recommendation. To sum up, it would appear that the Surface Go 3 has pushed or exceeded the capabilities of the power bank. In this situation, a power bank may overheat and shut down.

The best solution is to purchase a power bank with a higher power rating, so I would suggest getting one that can provide 100W of power with a high mAh rating. This way, you can charge both your phone and your Surface device.

To start, consider exploring popular brands such as Anker. For instance, the Anker 737 (PowerCore 24K) is noteworthy for its pricing, features, and warranty, although many other brands and options are also worth considering.

 

[Lobalobo]

Thanks, GoMan. I have now followed your advice and purchased a PD power bank that has 65W out of a single USB C port and it works perfectly.